Pick for mining-machines



(No Model.)

G. D. WHITOOMB.

PICK FOB. MINING MACHINES. No. 280,542. Patented July 3, 1883.

UNITED STATES GEORGE D. XVHITOOMB,

PATENT OFFICE.

OF CHICAGO, ILLINOIS.

PICK FOR MINING-MACHINES.

SPECIFICATIdN'forming part of Letters Patent No. 280,542, dated July 3, 1883.

Application filed November 10, 1882.

To all whom; it vnay concern:

Be it known that I, GEORGE D. WHI'rcoMB, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Picks for Coal-Mining Machines, 'which is fully set forth in the following specification, reference being had to the accompanying drawings, in which- Figure 1 represents a plan view of a pick embodying my present improvement, with its concave side uppermost; Fig. 2, a similar view of the same with its convex side uppermost; Fig. 3, a detail plan of one face of the convex side of the same near the cutting-edge; and Fig. 4, a transverse section taken on the line 00 m, Fig. 1.

My invention relates to picks for use in coalmining machines. In Letters Patent No. 232,792, heretofore issued to me, September 28, 1880, I have described and shown a form of pick for this purpose which is well adapted to the operation of mining-machines in ordinary coal; but I have learned from experience that it is desirable to provide coal-mining machines with picks of various forms adapted to work in different" kinds of strata and to cut passages of different shape. Coal differs in different mines, and sometimes the strata to be out are of a tough nature, and will not fracture freely under the blow of the pick, in which case, if the latter is of the form shown in my patent mentioned above, the cutting-face will not be left clean and comparatively even, but will be diversified by deep pockets or depressions and jagged projections, and on subsequent strokes the chisel-edged pick shown in the said patent will frequently glance off from the points of. the projections and strike in the pockets. I find that it is desirable to give the cutting-edge of the pick a wider field, so that there will be less danger of its striking on one side of the projections and glancing off.

It is the object of my present improvement to shape the cutting-edge of the pick so as to obtain the above-named result. In its main features of construction the pick is the same as that described and shown in my earlier patent construction of the point projection,

(No model.)

In the drawings, A represents the body of the pick, and B the cuttingedge thereof. The body of the pick is of a shape approaching a concavo-convex form in cross-section, though the metal is not bent on a true curve, but at somewhat of an angle-so that the convex side near the cutting-edge of the pick will present two faces, a a, nearly plain and standing very nearly at right angles to each other, while the concave side will present a similar conformation approaching a V shape, leaving faces a a standing at a similar angle to each' other toward the cutting-edge, as shown in Fig. 1 of the drawings. Farther back from the point the body may take a form more nearly c0ncavo-convex, if desired. The cutting-edge B will obviously be of a substantially angular contour. In this cutting-edge, at the end of each of the faces composing the body of the pick, as described above, a notched depression or scallop, .b, is made, as clearly shown in the drawings. These depressions or scallops extend nearly the width of the two faces, and

therefore leave three points-one, b, at the juncture of the two faces, and one, If, at each outer edge of these facesso that the cuttingedge in its entirety will consist of three points, two of which, b 12, stand in substantially the same plane, and athird, 12, standing in a plane outside of and to one side of the latter, with scalloped cutting-edges between the points. The central point, as shown in the drawings, has a rounded edge. It may be flattened slightly, however, if desired. The two outer points are shown as having a short, straight cutting-edge, as seen in Fig. 1 of the drawings; but this may be varied so as to make the points sharper, or provided with a rounded extremity, if desired. The points of the cutting-edge of this pick, it will be seen, stand at the three angles of a triangle, while the notched portions constitute two sides of the same triangle. I

The advantage of the operation of the pick having a cutting-edge of the shape described 5 with the shape of cutting-edge described above the field of attack is very considerably widened, and therefore in the greater number of instances the coal points will be taken between the points of the pick; or, it it enters pockets, it will strike on both sides, and hence the pick will obtain a hold upon the coal which will prevent it from glancing.

l'xhave described and shown the lower portion of the pick as formed with substantially two faces at an angle to each other; but I. do not limit myself s )eeiiica-ll v to this construction, for somewhat similar results may be obtained if the end of the pick is truly eoneavoconvex in cross-section. The term here shown and described is preferable, however, for the operation which I have herein set forth.

I am aware that pickshave been made with threepoints on the cutting-edge, having notches between them; but I believe I am the first to devise such a pick having the three points arranged at the three angles of a triangle whose plane is transverse to the length of the pick.

Having thus described my invention, what I claim. and desire to secure by Letters Patent,

1. In a coal-mining machine, a pick provided with a cutting-edge having three points, two of which are arranged in the same plane, and the third in a plane outside of the former, with notches in the edge between them, sub stantially as described.

2. A pick for coal-mining machines, provided with a cutting-edge, 3, composed of two notched chisel-edges, I), arranged at an angle to each other, and three points, I) b" b", arranged at the three angles of a triangle, sub stantially as described.

3. A pick for a coal-1nining machine, the lower end of which is shaped to form twosubstantially plain faces, (1, arranged at an angle to each other, and provided at their extremities with notched cutting-edges band points I) If, substantially as and for the purposes set forth.

GEO. D. I-II'DUOlW'I-Z.

Witnesses:

J'No. U. BIACGREGOR, THOMAS H. lmsn. 

